Haven't actually read it yet but from seeing Japanese reader reviews, it seems that there's no clear wife, he have daughter but even until the latest completed LN the author never ever mentioned who the wife is. The author seemingly just let the readers cast a dice and randomly decide who the wife is... I think the author chickened out and keep things vague since he can't pick the heroine himself, not only the MC, the author is too cowardice... http://bookmeter.com/bl/4072947059